Duluth fog whistle

[Guest]

I've never heard the horn blowing in Manistee but their is a sign on the lighthouse that reads "To energize fog horn key channel ### 3x's. So someone could have done something like that. Also some (not sure if this is true on the lakes) lighthouses use and IR or Laser and if the beam is reflected by something (I.E. fog) the horn activates. When I was working on the ships there was a few times we passed the crib lights in Northern Lake Michigan on clear days and the signals would be sounding, I always thought it had something to do with pressure or humidity.

[garbear]

I know every Wednesday afternoon, if no severe weather is in the area, is when the weather sirens are tested. It's usually between 1-1:30 pm. I can usually hear them from my place. Don't know about the bridge.

[Paul A]

I just watched the Mesabi Miner enter Duluth on line at 1553 cdt and the fog signal was going the whole time even though it was mostly sunny. Do they test these like the severe weather sirens or was something else going on?